conduit testing

[Bradzz]

Hi all. I was wondering when completing a EICR when you have conduit as the cpc in a ring what do you input into the section r2. the end to end r2 reading. NOT THE R2.
do you leave that section blank. and just perform your R1+R2 reading, along with the end to end readings of the phase and neutral.
r1 .34/ r2 blank/ rn .34 / R1+R2 = your reading with the phase and conduit linked out at db.
Cheers all

 

[i=p/u]

il guess you go from one end to other end with wonder lead

 

[Amp David]

I wouldn't leave it blank, N/A instead.

Your R1+R2 test as you described would confirm the conduit is doing its job properly.

 

[tigerpaul]

Agree with amp david

 

[johnboy6083]

I would do as amp said, Record R1+R2, and make a note that you are using conduit as CPC. Your Zs is the reading that is the most important.

 

[Adam]

I wouldn't leave it blank, N/A instead.

Your R1+R2 test as you described would confirm the conduit is doing its job properly.

Just out of interest, how do you test your R1+R2 on a ring main in conduit that is using the conduit as CPC? Obviously, you can't to the usual figure of eight testing.

I've always done R2 tests in this situation.

 

[johnboy6083]

fair point

 

[Amp David]

Just out of interest, how do you test your R1+R2 on a ring main in conduit that is using the conduit as CPC? Obviously, you can't to the usual figure of eight testing.

I've always done R2 tests in this situation.

Very true Adam.

Impossible without isolating the conduit from the DB lol :tt1:

A case of typing away without thinking the question through first.

 

[tigerpaul]

What if you short the lines down to the earthing terminals at the DB, then measure at each socket. Record your highest reading.

 

[Amp David]

The conductors won't be crossed then.

 

[tigerpaul]

You can still check for spurs and interlinks in the ring by doing the test with L and N.
R1 + R2 is the resistance of the line and cpc so testing as I said is still valid. It's similar to testing a circuit that is parallel fed.

 

[Gritishbasspark]

I would wander lead every socket just test the integrity of the joints on the conduit record the highest reading also in the cpc size column on the test cert you can put con.

 

[ackbarthestar]

You can still do the figure of eight test between L-N.
The L-E, R1 + R2, you might measure, using the long lead test at the furthest physical outlet.

It still doesn't guarantee that the conduit R2 is suitably connected. You may need to use an old test method such as an ac earth continuity tester which generates 50V ac at 1.5 times the design current of the circuit up to a maximum of 25A.

I haven't seen one of these for years.

 

[Engineer54]

You may need to use an old test method such as an ac earth continuity tester which generates 50V ac at 1.5 times the design current of the circuit up to a maximum of 25A. I haven't seen one of these for years.

Still very much available, we have used these Ductor type long lead earth continuity testers on all of the major projects i've been involved on, for testing our extensive metal containment systems . I do believe though, that on the most recent projects these testers were of American origin. Those that i've used in the past and in the UK, were i believe normally made by ''Clare industries''.....